Tomás Díaz Valdés

Effectiveness of Different Doses of Diatomaceous Earth on Mexican Bean Weevil (Zabrotes subfasciatus Boheman) in Culiacan, Sinaloa, Mexico

The objective of this research was to determine the effectiveness of different doses of diatomaceous earth (TD) against bean Mexican weevil Zabrotes subfasciatus Boheman. An experiment was carried out in two phases: in first one tested diatomaceous earth at doses of 1.0, 2.0, 3.0, 4.0 and 5.0 g·kg﹣1 of seed, with samples at 15, 30, 45 and 60 days after application (dda), while in the second the doses were 0.2, 0.4, 0.6, 0.8 and 1.0 g·kg﹣1 and samples at 10, 20, 30 and 40 dda. The parameters evaluated were weevil mortality and seed germination. The results indicated that the average mortality rate was 100% where deltamethrin and diatomaceous earth were applied at 4.0 and 5.0 g·kg﹣1 of seed, with the 3.0 g·kg﹣1 dose was 97.6%, with 2.0 G·kg﹣1 was 97.0%, with 1.0 g·kg﹣1 reaching 94.4%, whereas in absolute control mortality was 1.2% - 2.5%. A similar response was observed with lower doses of diatomaceous earth (0.6, 0.8 and 1.0 g·kg﹣1) and the chemical Deltamethrin, which caused 100% mortality, with a dose of 0.4 g·kg﹣1 was 90% - 98%, with 2.0 g·kg﹣1 from 62% to 83%, whereas in the absolute control there was no mortality. The treatments did not inhibit seed germination in the two experimental phases, whose percentage ranged from 94% to 96%.